JPH0132444B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for automatically calculating an accurate travel distance of a vehicle traveling on a track.

BACKGROUND ART Conventionally, in order to detect the travel distance of a track-running vehicle such as a track inspection vehicle, a method of detecting and integrating the rotational speed of an axle directly connected to a wheel has been widely used. However, relying solely on the above method introduces errors due to reduction in size due to wheel wear and wheel slippage.

In order to correct the above-mentioned errors, conventionally, a method has been used in which distance markers are installed along the track and distance marker detectors are mounted on track-traveling vehicles to detect points.

Since there are essential advantages and disadvantages between the above-mentioned mileage calculation based on the wheel rotation speed and mileage calculation based on the distance marker, accurate and detailed mileage can only be detected by using both together.

In other words, although there is a risk of the above-mentioned error being introduced when calculating the distance traveled based on the number of wheel rotations, it has the advantage of being able to detect even minute units in an analog manner, and for example, it is possible to calculate the distance traveled in units of 1 meter. It is. In comparison, mileage calculation based on distance markers has absolute accuracy, but has the disadvantage that mileage can only be detected in digital coarse units. Theoretically, it is possible to detect the distance traveled in units of 1 meter by installing a distance marker every 1 meter, but it is difficult and impractical to actually install a distance marker every 1 meter.

Due to the above-mentioned circumstances, conventionally, the distance traveled is calculated continuously based on the number of rotations of the wheels, and at the same time, the actual distance traveled is intermittently detected based on the distance marker, and the calculated distance is corrected. method is used. As a result, it is possible to calculate a detailed mileage in units of, for example, 1 meter, while correcting the error every 100 meters to match the exact mileage, and thus obtain mileage information with sufficient accuracy for practical use.

However, in the conventional method as described above, if it is attempted to automatically perform the mileage correction work using a hard circuit, a large-sized device using a large number of circuit blocks is required.

The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide a distance pulse control method that can automatically calculate a travel distance accurately and in detail using a small device.

In order to achieve the above object, the present invention installs distance markers at regular intervals along the track, and
A vehicle running on the track is provided with a point detector for detecting the above-mentioned distance marker and a wheel rotation speed detector, and a distance pulse signal which is the output of the above-mentioned rotation speed detector and a signal output from the point detector are provided. is input into a computer, and a comparison calculation is made between both signal outputs to calculate the travel distance, and calculation errors due to wheel wear are automatically corrected.

Specifically, when the distance pulse signal interval is L, the number of times of the distance pulse signal is i, and the distance traveled is accumulated by S=i・L, N
is a positive integer, and calculates whether N≦i・L holds true for each distance pulse signal input, and when it holds, outputs a pulse corresponding to a unit length, and for each pulse, the unit length increases. In addition to displaying the mileage by counting up, when the point detection signal is input, the value of L is corrected so that the cumulative mileage value S matches the distance indicator scale. do.

FIG. 1 is a schematic block diagram of one embodiment of calculating a travel distance by applying the method of the present invention.

The distance pulse, which is the signal output of the axle pulse generator 1, and the signal output of the point detector 2 are input to the microcomputer 4, and the unit pulse obtained by performing calculations described in detail later with reference to FIG. In this example, a 1 m pulse is assumed to simplify the explanation) is input to the data recorder 5. When carrying out the present invention, instead of the above-mentioned pulse every 1 m, it is also possible to configure the system so that a pulse is input every fixed distance other than 1 m.
(In the present invention, a 1 m pulse includes a pulse to indicate the minimum unit for displaying a running distance, and is not limited to a pulse every 1 meter in the metric system). In addition, the above-mentioned 1m pulses are integrated using a calculation method that will be described in detail later, and the travel distance is calculated and displayed on the travel kilometer display 6. Since the above calculation is simple as will be described later, a small microcomputer is sufficient. Furthermore, if an existing medium-sized computer has extra capacity, it can also be used.

FIG. 2 is a chart showing the timing at which one of the distance pulses obtained from the axle directly connected to the wheel is output as a 1m pulse.
B is the distance pulse obtained from the rotation speed of the axle, B is the distance pulse obtained from the rotation speed of the axle, and C is the one closest to 1 m among the above distance pulses as described below. Each shows a 1m pulse.

The distance pulse pulses based on the rotational speed of the axles directly connected to the wheels serve as the original data for distance calculation in the method of the present invention (hereinafter, these will be abbreviated as original pulses P ₀ , P ₁ , . . . ).

The traveling distance S obtained by integrating the original pulses P ₀ , P ₁ , . . . is given by the following equation.

S=i・L[M] ...(5.1) where i: Number of original pulses L: Interval of original pulses (in meters) Equation (5.1) above generally includes a fraction, so this should be corrected and the number below the decimal point The following formula is used to truncate.

N-i・L≦0……(5.2) However, N is a positive integer.

The microcomputer 4 calculates equation (5.2) every time the original pulses P ₀ , P ₁ , .

Next, in order to calculate the travel distance, the travel distance display 6 is counted up by +1 [M] for each 1 m pulse. However, N in the above equation (5.2) is initially set to 1, and is added by +1 for every 1m pulse output. Due to the truncation according to the above equation (5.2), the 1m pulses shown in Figure 2 are slightly irregularly spaced compared to the exact m points of 1m, but this does not cause any practical problems.

Assuming that there is no wheel wear or slippage, the mileage is calculated with an extremely small error due to the above effects, but in reality, the reduction in diameter due to wheel wear and the effects of wheel slippage are corrected. Must be corrected to the correct value. Here, wheel wear is a phenomenon that cannot be restored, so when wear is detected, constants in subsequent calculations must be corrected, whereas slip is a temporary phenomenon, so a one-time correction is sufficient. , there is no need to touch the constants in subsequent calculations.

Next, an embodiment of a method for detecting reduction in wheel size due to wear and correcting travel distance will be described.

In this example, the present invention is applied to a track inspection vehicle, in which the number of original pulses is set to 3200 pulses/km when there is no wear or abnormal slip on the wheels, and the distance marker is
Installed every 100m.

The original pulse interval is 1000m/3200=0.3125m. Therefore, if this wheel runs without slipping, the original pulse will match the detection pulse of the distance marker every 320th distance marker for 100 m.

However, as the wheel diameter wears out and decreases, the timing that matches the original pulse for every 320 point detection pulses will be disrupted, so the timing will change while the distance markers can be calculated for an appropriate number of sections, for example every 500 sections (equivalent to 50 km). The diameter of the wheel is calculated backward from the number of original pulses, the average value of the original pulse intervals is found, and the original pulse interval is corrected based on this. In other words, the original pulse interval is (5.1)
By transforming the equation, it is given by the following equation.

L=S/i (5.3) However, the value of S is assumed to be large enough to average out the variations in the original pulse intervals as described above.

Each time L is calculated using equation (5.3) above,
Substitute this value into (5.1) above.

When using this method, 1 m pulse becomes m
The probability of exactly matching the point is smaller than 1/16 when the wheel diameter is not worn, but
Even if the difference between the 1m pulse and the point m is estimated assuming the worst conditions, it is much smaller than the original pulse interval of 0.3125m, so it can be ignored.

FIG. 3 is a flowchart of calculations performed by the microcomputer 4. In flow 9, the value of L in the above equation is set. X is the generation distance interval of the original pulse, and its value changes depending on the wear of the wheels, but the initial state is the standard number 1000 mentioned above.
(m)/3200=0.3125 is used.

The R register of flow 10 is 1m from the original pulse.
This is a register for selecting pulses, and the value corresponding to 1m is R ₀ .

When the original pulse is input in flow 11, the process proceeds to flow 12, where L is subtracted from the R register. The calculation is as shown in the following equation.

R _j = R ₀ −j・L (5.5) where, j: The number of inputs of the original pulse starting from the time when the 1m pulse was output or from the time when the R register was initialized.

R _j ; Contents of the R register after the j-th original pulse is input and calculated.

Next, in flow 13, the content of R _j is checked, and if R _j is zero or negative, it is determined that the track inspection vehicle has traveled a distance of 1 m, and in flow 14, a 1 m pulse is output, and again in flow 15. Increase the number of kilometers traveled by +1. Furthermore, in flow 16, the R register is rewritten, ie, reset.

R ₀ ′=R ₀ +R _j ……(5.6) Here, R ₀ ′ is the content of the newly reset R register, and after the operation of equation (5.6), j in equation (5.5) becomes 0.
is set to Equation (5.6) is an arithmetic expression for the fraction described in Equation (5.1), and is an operation for removing errors due to the fraction during the calculation process for the original pulse.

If there is no input of the original pulse in flow 11, proceed to flow 18 and check the input of the point detection signal obtained by detecting the distance marker, and if the point detection signal is input, first check the mileage traveled. Check the validity of the input point detection signal. In other words, since a valid point detection signal is generated every 100 [M], the distance traveled when the point detection signal is input should indicate a value close to an integer multiple of 100 [M]. be. Small slips often exist even under normal driving conditions, so
It is not necessarily an exact integer multiple.

Therefore, if the distance traveled when the point detection signal is input is within ±20 [M] of an integer multiple of 100 [M], this is considered to be a true point detection signal, and the distance traveled is calculated. Correct it to an integral multiple of 100 [M]. Next, in flow 21, it is checked whether the point detection signal has been input 500 times. This is a survey to determine whether the track inspection vehicle has traveled 50 [KM]. If it has traveled 50 [KM], then in flow 22, the total number of original pulses N _P generated during 50 [KM] is calculated. Check using the formula below.

A _P = N _P − [50 (KM) × 3200] ... (5.7) Where A _P ; Wheel wear measured between 50 [KM]. and the number of original pulses generated by slips, etc.

The calculation result A _P of equation (5.7) is the sum of the excessive original pulses generated due to wheel wear and the incorrect original pulses generated due to slips, etc. However, judging from the degree of wear of the wheels and the frequency of slips, the number of original pulses in the latter is very small compared to the former at a distance of 50 [KM].
Further, over a certain distance, the former original pulse number is a substantially stable value, but the latter is an unstable value due to the cause of its occurrence. Due to the above circumstances, in order to minimize the influence of wheel slip etc. and perform the correction due to wheel wear using A _P (that is, back calculation of the original pulse interval L), the following equation must be satisfied.

A _P ≫ B× [50 ₍ KM) If it rotates, it is excluded from the wear correction calculation. The lower limit is determined by considering the wear limit of the wheels as well.
Empirically, it is appropriate to set it at about 150 for a distance of 50 [KM]. In flow 24, the original pulse interval L is calculated. The calculation formula is shown in (5.3) above.
The formula is S is 50 [KM].

This allows accurate travel distance to be calculated in meters, with the effects of wheel wear and slippage corrected.

As described in detail above, the distance pulse control method of the present invention involves installing distance markers along the track, and installing a point detector for detecting the distance marker on a vehicle traveling on the track, as well as a wheel rotation speed sensor. The distance pulse signal output from the rotation speed detector and the signal output from the point detector are input into a computer, and the distance traveled is calculated by comparing the signal outputs of both. By automatically correcting calculation errors caused by wear, it is possible to accurately and precisely calculate mileage by using small automatic calculation equipment such as a microcomputer, or by utilizing the extra capacity of other medium-sized computers. It can be calculated automatically.

[Brief explanation of drawings]

1 to 3 show an embodiment of the distance pulse control method of the present invention, FIG. 1 is a schematic block diagram, FIG. 2 is a timing diagram showing a 1 m pulse,
Figure 3 is a flowchart. 1...Axle pulse generator as a wheel rotation speed detector, 2...Point detector, 4...Microcomputer, 5...Data recorder, 6...Driving km display.

Claims (1)

[Claims] 1. Distance markers are installed along the track, and
In a method in which a vehicle running on a track is provided with a point detector for detecting the above-mentioned distance marker and a wheel rotation speed detector, and a distance pulse signal proportional to the traveling distance is outputted, the distance pulse signal and the above-mentioned distance pulse signal are Input the signal output of the point detector into the computer, let the distance pulse signal interval be L, and let the number of times of the distance pulse signal be i. When accumulating the distance traveled by S=i・L, N
Let N be a positive integer, and for each distance pulse signal input, N
It calculates whether or not -i・L≦0 holds true, and when it holds true, outputs a pulse corresponding to the unit length, counts up the unit length for each pulse, and displays the distance traveled. , A distance pulse control method, characterized in that when the point detection signal is input, the cumulative mileage value S is corrected by resetting the value of L so that it matches a distance marker scale. .